Skewing device for dampener of offset printing press

ABSTRACT

A wetting mechanism for transferring liquid from a supply roll which is immersed in a liquid reservoir to a lifting roll. The supply roll and the lifting roll are peripherally engaged. The axes of the rolls are in a common plane. The supply roll is mounted on a support plate and both are pivoted about a center pivot. The pivotal movement is caused by moving a lever which is connected to a cam which engages a camming surface on the support plate.

Q Umted States Patent 11113,625,144

[72] Inventors Robert Reinartz [56] References Cited Augsburg; UNITED STATES PATENTS Hebe", westheim Germany 1 029 239 6/1912 Smith 101/148 [2 P rgin 2,165,234 7/1939 Curtis 101/148 [22] He Y 9 3,343,484 9/1967 Dahlgren 101/148 [45] 7,1 71 3.433155 3/1969 Norton 101/148 [73] Asslgnee Maschinenfabrik Augsburg-Nurnberg AG OTHER REFERENCES Augsburg, Germany [32] Priority July 26, 1968 Gegenheirner, Harold W What s New in Offset Dampen- [33] Germany mg Systems, Inland Prmter, Feb. 1964 [31 l P 17 61 949'7 Primary Examiner- Robert E. Pulfrey [54] SKEWING DEVICE FOR DAMPENER OF OFFSET PRINTING PRESS 6 Claims, 5 Drawing Figs.

[S2] U.S. Cl 101/148, 101/363 [51] Int. Cl B411 25/02 [50] FieldolSearch 101/147, 148, 335, 348, 349, 350, 363, 205, 206, 207, 208, 210

Assistant Examiner-R. E. Suter AttorneyBauer and Goodman camr ning surface on the support plate.

SKEWING DEVICE FOR DAMPENER OF OFFSET PRINTING PRESS BACKGROUND OF THE INVENTION Ofiset printing presses contain a liquid distribution mechanism to apply a thin uniform film of liquid to rolls, as described in, e.g., US. Pat. No. 3,144,826. US. Pat. No. 3,246,601 discloses a liquid supply roll partially immersed in a reservoir. The supply roll transfers water to a lifting or vibrating roll positioned above the supply roll. The lifting roll in turn supplies water to the distributing roll. Similar mechanisms may be used to convey liquid to other rolls such as inking rolls.

When the supply of water or fountain liquid to the rolls of a rotary offset printing press is insufficient, tinting may occur. With an excess of water, emulsification occurs which greatly impairs the gloss of the ink. It is important that the correct amount of water be supplied to the rolls and that it should be supplied uniformly across the distributing roll. This requires uniform distribution along the supply roll.

It has been found that the end zones of the supply roll often contain insufiicient water. The amount and uniformity of the water layer on the supply rolls is effected when a guide roll which moves along the side of the supply roll is used. The lever action of the guide roll apparently squeezes water over the sides of the supply roll resulting in an insufficient supply of water at the end zones of the supply roll. This causes a corresponding condition on the lifting roll.

It has been suggested that this condition may be prevented and a larger volume of water conveyed by continuously adjusting the angle of rotation of guide roll in the longitudinal direction. This has not prevented nonuniform distribution with excess water at the center of the roll and insufficient amounts of water at the ends. The use of long longitudinal squeegee strips of felt, metal, or a similar material, has also been used to obtain uniform wetness across the roll. This requires expensive equipment and is time consuming. Brushwetting mechanisms have also been tried without success to precisely control the film of water across the roll. The use of multiple nozzles along the length of the supply roll to blow away excess water and obtain uniform distribution has also been tried. This requires additional equipment including a compressor. It has also been found difficult to precisely adjust the thickness of the film of water using these multiple nozzles.

It is an object of the present invention to provide a reliable precise water-distributing mechanism of economic construction in which the water film on the supply roll is controlled to obtain a uniform thin film.

SUMMARY OF THE INVENTION The present invention provides an improved wetting mechanism for transferring a film of liquid from a supply roll to a lifting roll. The supply roll is positioned to be partially immersed in a reservoir. A lifting roll is positioned in peripheral engagement with said supply roll. The axes of said rolls are in a common plane. The improvement comprises means connected with said supply roll to pivot the axis thereof out of said common plane with said supply roll remaining in peripheral engaged relationship with said lifting roll.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a vertical cross section through a portion of the wetting mechanism;

FIG. 2 is a plan view of the wetting mechanism;

FIG. 3 is a side view in partial section of another embodiment of the mechanism;

FIG. 4 is a section through IV-IV' of F IG. 1; and

FIG. 5 is a section through V-V' of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, in which like reference characters refer to like parts throughout the several views thereof, there is indicated somewhat diagrammatically a wetting mechanism 10 mounted between the sidewalls 12 of a rotary printing ress. The right-hand portion of the mechanism 10 is not depicted since it is not required to illustrate the invention. The wetting mechanism 10 is part of and mounted on a base 14 which is fixed between the sidewalls 12 of the printing press. The base 14 is preferably an inverted U-shaped bar and supports a plate 16 which may be pivotally moved about a pivot bolt 18.

A liquid reservoir 20 is mounted on supports 21 which are carried on the plate 16. The plate 16 also indirectly supports a liquid supply roll 22 which is directly supported on end supports 25 and is positioned to be partially immersed in the liquid reservoir 20.

The liquid supply roll 22 is driven by a motor 24 through reduction gears 26. The motor 24 and the reduction gears 26 are directly supported by the plate 16 (FIG. 2). FIG 3 illustrates another embodiment of the invention wherein the motor 28 and the reduction gears supply are mounted outside the sidewalls l2 and drive the SUPPLY roll 22 through universal joints 32 and a shaft 34.

A lifting roll 36 (the term lifting roll" is meant to include vibrating rolls see the aforereferred to US. Pat. No. 3,246,601, particularly Col. 2, lines 50-58) takes the water from the supply roll 22 and conveys it to a distributor roll on the press (not illustrated). The lifting roll 36 is positioned above and in peripheral engagement with the supply roll 22. The wetting mechanism 10, including the axis of the supply roll 22, is usually positioned in a substantially horizontal plane. The relative positioning of the supply roll 22 and the lifting roll 36 is affected in slight angular amount by pivotal movement of the axis of the supply roll 22 around a vertical axis. This is accomplished by pivoting the support plate 16 about pivot bolt 18. The plate 16 is pivoted by rotation of a lever bolt 37 which extends through base 14 into an eccentric cam 40 positioned in a recess 42 defined in plate 16. Rotation of the lever bolt 37, by turning the handle 38, causes the plate 16 to pivot about the pivot bolt 18. This causes conjoint movement of the reservoir 20 and the supply roll 22 together with its associated drive so that all of these parts remain in their original relationship.

The amount of lateral movement of the end 44 of the supply roll 22 is relatively slight. Thus, the difference in distance, measured in a vertical plane coinciding with the left end 45 of the lifting roll 36, between the axis of the lifting roll 36 and the axis of the supply roll 22 before and after pivoting, is only about 2/10-3/10 mm. The magnitude of the pivotal movement is further illustrated by the following: For a supply roll 1.5 meter long having a mm. diameter (the lifting roll also having a 90 mm. diameter), the lateral movement of the center of the left end 44 of the supply roll 22 is between about 5 mm. and 8 mm. when pivoted out of the initial common vertical plane of the axes of said rolls.

To further control the water distribution along the supply roll 22, one or more guide rolls 46 are provided to move axially alongside of the supply roll 22 on a guide slide 48. The amount of pressure applied by the guide roll 46 against supply roll 22 is controlled by turning an adjustable pressure screw 50.

Support plate 16 may be fixed to base 14 by one or more setscrews 52.

Fine adjustment of rotary printing presses is usually carried out while the press in in operation. This is particularly useful when adjusting the supply and distribution of liquid, e.g., ink, water, etc. The wetting mechanism of the present invention permits accurate adjustment of the amount and distribution of the liquid along the supply roll 22 to be made while the press is in operation. This is accomplished with an economic and simple construction.

We claim:

1. A wetting mechanism for transferring a film of liquid from a supply roll to a lifting roll comprising a base support,

a support plate,

a liquid reservoir mounted on said support plate,

a supply roll mounted on said support plate and positioned to be partially immersed in said reservoir,

a lifting roll positioned to be peripherally engaged with said supply roll,

a pivot connecting said base support and said support plate, said pivot being positioned at the center of the roll length, and a single means for pivotally moving said supply roll about said pivot, said single means consisting of a camming surface formed in one end of said support plate,

a cam engageable with said camming surface, and

a lever means mounted on said base support and connected with said cam,

whereby upon movement of said lever means, said support plate is caused to pivot about said center and to move angularly relative to said base support causing an angular displacement of said supply roll relative to said lifting roll.

2. The wetting mechanism of claim 1 wherein said camming surface is a recess defined in said support plate, wherein said cam is an eccentric cam positioned in and engageable with the defining walls of said recess and wherein said lever is connected with said cam so that rotation of said lever causes said support plate to pivot.

3. The wetting mechanism of claim 2, said mechanism including a drive motor and a power transmission drive connecting said drive motor and said supply roll, said drive motor and said power transmission drive being mounted on said support plate.

4. The wetting mechanism of claim 3 wherein said base support is a U-shaped member.

5. The wetting mechanism of claim 2, said mechanism containing a drive motor and a flexible power transmitting drive connecting said drive motor and said supply roll.

6. The wetting mechanism of claim 5 wherein said support bar is a U-shaped member. 

1. A wetting mechanism for transferring a film of liquid from a supply roll to a lifting roll comprising a base support, a support plate, a liquid reservoir mounted on said support plate, a supply roll mounted on said support plate and positioned to be partially immersed in said reservoir, a lifting roll positioned to be peripherally engaged with said supply roll, a pivot connecting said base support and said support plate, said pivot being positioned at the center of the roll length, and a single means for pivotally moving said supply roll about said pivot, said single means consisting of a camming surface formed in one end of said support plate, a cam engageable with said camming surface, and a lever means mounted on said base support and connected with said cam, whereby upon movement of said lever means, said support plate is caused to pivot about said center and to move angularly relative to said base support causing an angular displacement of said supply roll relative to said lifting roll.
 2. The wetting mechanism of claim 1 wherein said camming surface is a recess defined in said support plate, wherein said cam is an eccentric cam positioned in and engageable with the defining walls of said recess and wherein said lever is connected with said cam so that rotation of said lever causes said support plate to pivot.
 3. The wetting mechanism of claim 2, said mechanism including a drive motor and a power transmission drive connecting said drive motor and said supply roll, said drive motor and said power transmission drive being mounted on said support plate.
 4. The wetting mechanism of claim 3 wherein said base support is a U-shaped member.
 5. The wetting mechanism of claim 2, said mechanism containing a drive motor and a flexible power transmitting drive connecting said drive motor and said supply roll.
 6. The wetting mechanism of claim 5 wherein said support bar is a U-shaped member. 